When it comes to hard rock applications, mining operators rely primarily on Jaw and Gyratory crushers. While these are suitable and proven for such applications they require large installation heights.
Enter thyssenkrupp’s Eccentric Roll Crusher (ERC). Launched earlier this year, the compact and robust ERC is suitable for both surface and underground operations.
Demitri Kokoroyanis, product manager, minerals processing, crushing and screening technology explains that the crusher is designed for easier operation with wet sticky material and very hard materials in excess of the conventional primary crushers.
“The ERC combines the ability to process hard rock material with a low profile machine design resulting in less installation height and machine weight. High moment of inertia of roll and flywheels reduce power requirements and improves energy efficiency.
"In addition, the integrated pre-screening device allows for efficient bypassing of fines, reduced wear and higher machine capacity,” he states.
This next generation crusher features a fully hydraulic gap setting/retraction system which allows for automatic adjustment of the gap, compensation of liner wear and release of tramp metal or otherwise uncrushable material content.
“The ERC can also crush large hard lumps for example, our ERC 25-25 model has a roll diameter of 2500 mm by the width of 2500 mm which can receive large lumps up to 2000 mm x 1500 mm x 1000 mm and crush down to a crushing ratio of 1-6,” Kokoroyanis adds.
Cost effective mining alternative
Kokoroyanis further explains that the challenge for the applied crushing technology is primarily the limited space available in the underground tunnels and chambers, which results in special requirements for a crusher design.
Due to their large overall height, both Jaw and Gyratory crushers have the disadvantage of requiring the construction of large-volume and cost-intensive chambers for underground operations and also for new mines where no natural bench is available and has to be erected The ERC has major advantages as it requires less bench height.
thyssenkrupp’s first prototype ERC 25-25 model was tested in an open pit application in Germany.
The crusher was subjected to extensive tests with the objective of the test operation, was to determine relevant operating parameters and process data under real conditions in order to prove the suitability of the crusher for the ore and hard rock industry.
In the selected mine a hard andesite was extracted – a material comparable to some copper ores and iron ores.
The crushing plant used for the tests consisted of a feed hopper, a vibrating feeder, the crusher with integrated primary scalping grizzly, a discharge belt conveyor, steel structure and a power unit.
The most important process and machine parameters were determined in a test operation lasting more than six months. In all parameters, the machine met and surpassed the requirements.
Currently, the first ERC 18-14 model has been commercially sold and is in the ramp up stages to full production in an open pit mining application in Germany.
Furthermore, the company is currently in consultation with some its clients in the Sub Sahara region in new greenfield projects.
However, as Kokoroyanis explains, thyssenkrupp focus in not just on supplying a cost-effective primary crusher range to its clients.
“Rather, we are closely involved with our well known clients due to selecting and custom designing the best crusher for the application and making sure all the basis are covered for long and safe operational life of mine,” he concludes.